You may want to link to a layer from your app or mobile site so that a user can launch your layer within the Layar app. In this case, you need to make use of Layar intents. Intents can be used generally for interaction, for example in websites or e-mails.
General best practice is to use http://m.layar.com/open/layername. It will open a web page allowing the user to directly open the layer from that page; or, if the Layar Browser is not installed, download the app from the market for that platform. Some people might want to use layar://layername intent since it will open the layer directly. However, please NOTE that it will only work properly if the Layar App is already installed. Otherwise, nothing will happen, resulting in a poor user experience. Therefore, we recommend using the http link mentioned above.
The technical details of Layar intents can be found here.